<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
	<input type="button" id="btn" value="获取验证码" />  
		<script type="text/javascript">  
			var wait=60;  
			function time(o) {  
        if (wait == 0) {  
            o.removeAttribute("disabled");            
            o.value='获取验证码';  
            wait = 60;  
        } else {  
            o.setAttribute("disabled", true);  
            o.value=''+wait +'s重新发送';  
            wait--;  
            setTimeout(function() {  
                time(o)  
            },  
            1000);
        }  
    }  
document.getElementById("btn").onclick=function(){time(this);}  
</script>  
	</body>
</html>
